JPS6010540A - Assembly method of metal parts in color crt - Google Patents

Abstract

PURPOSE:To obtain stable welding strength by bringing multiple metal parts formed with a blackened film enclosed in a tube in contact with predetermined positions by use of a positioning unit respectively then welding them with laser rays. CONSTITUTION:A black film is formed on a shadow mask 4, a frame 6, an inner shield 7 enclosed in a tube. A panel 1 fitted with the mask 4 is mounted on a working table 10, a positioning bar 16 is driven upward to get in contact with a positioning plate 13 for positioning, and it is hung with a vacuum chuck 17. Next, a magazine 20 mounted with the inner shield 7 is fed, and the shield 7 is positioned at a predetermined position of the frame 6 with a sway arm 23 having a vacuum chuck 22. A laser ray passing hole is formed on one side of the shield 7, and the other side edge where this passing hole is not formed is brought into contact with the frame 6. Under this condition, laser rays 26 are illuminated to a weld 24 to be welded through the hole, and stable welding strength can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for assembling a metal component coated with a blackened film and incorporated in a color cathode ray tube.

[Technical Background of the Invention] Generally, the internal structure of a color cathode ray tube is as shown in FIG. A funnel 3 that is fixed in a positional relationship, a shadow mask 4 that blocks unnecessary electrons to create an image, and a shadow mask 4 that is fixed to the panel 1 by a fixed bin 5 are held at a position a certain distance apart from the panel 1. and an inner shield 7 that blocks the electron beam outside the effective area and protects the electron beam from external magnetic fields.

FIG. 2 is a perspective view showing the assembled state of the shadow mask 4, frame 6, and inner shield 7 among the metal parts built into the color cathode ray tube, and FIG. 3 is a partial vertical cross-sectional view after the assembly. .

The shadow mask 4 has fixing pins 5 shown in FIG.
A holder 8 that fits into the frame 6 is welded to the frame 6, which has a cross-sectional shape, and is fixed by resistance welding at several points, and an inner shield 7 whose cross-section has an enlarged opening and a cross-sectional shape similar to that of an opening or a U-shape is also similar. and is fixed to the frame 6. In FIG. 3, reference numeral 9 indicates a welded portion that joins these metal parts.

These metal parts, namely the shadow mask 4, the frame 6, and the inner shield 7, are designed to absorb thermal energy from the electron beam that falls inside the tube. To prevent diffused reflection of light, a luminescent oxide film (Fe 3
04) (blackened film) is applied.

[Problems with blue technology However, such conventional metal assembly has the following drawbacks.

(a) Since the electrical resistance of the blackened film formed on the surfaces of the shadow mask, frame, and inner shield is high, the welding current value varies depending on the state of this coating, and the welding strength changes.

(b) Ultra-thin metal parts undergo plastic deformation because a large pressing force is required to facilitate the flow of welding current.

(c) Since the metal parts are heated over a wide range by the welding current, a large amount of blackened film peels off and scatters in all directions (
splash), which may adversely affect the product.

[Object of the Invention] The present invention has been made to solve the above-mentioned problems, and provides a method for welding metal parts in color cathode ray tubes, which provides stable welding strength and does not require pressing force that would deform the metal parts. An assembly method is provided.

[Summary of the Invention] The method for assembling a color cathode ray tube of the present invention involves positioning a plurality of metal parts on which a blackened film is formed, which is built into a color cathode ray tube, at a predetermined position using a positioning device. They are brought into contact with each other and then welded together using a laser beam.

[Embodiments of the Invention] Details of the present invention will be shown in the drawings and one embodiment will be described below. In the following figures, parts common to those in FIGS. 1 to 3 are denoted by the same reference numerals.

FIG. 4 is a sectional view showing the process of fixing the shadow mask 4 and frame 6 to the panel 1 with fixing pins 5, positioning them with a positioning device, and preparing to attach (pull) the inner shield.

The positioning device shown in FIG. 4 and the following figures includes a main body plate 11 equipped with a movable table 10 on the upper surface that can move a mounted panel 1 in any direction, a base 12 provided approximately in the center thereof, An arm 14 that supports the positioning plate 13 on the base 12 so that it can slide outward -C, and an arm 1
The cam arm at the base of 4 is in contact with the cam arm 15 of the C arm 1.
4 and a positioning monthly salary cam 16 that slides.

At least one arm is provided on each of the four sides of the frame 6, and at least four arms in total are provided.

To position the frame 6 using this positioning device, first place the panel 1 on the operating table 10 of this device, drive the positioning monthly salary cam 16 upward to spread the arm 14 outward, and then move the positioning plate 1 is brought into contact with the frame 6. The fixed panel 1 of the frame 6 is freely movable on the movable table 10 and is positioned so that its center coincides with the axis of the cam 16 of the C1 positioning device.

After positioning the frame 6, the panel 1 is lifted up by a vacuum chuck 17 and a lid 19 provided with three or four wooden stoppers 18 erected around the vacuum chuck 17.

Next, as shown in FIG. 5, below the panel 1, an inner shield magazine 20 carrying a set of inner shields 7 with the opening facing upward is fed.

The inner shield 7 includes a swing arm 2 provided at both ends of a center part 21 and having a vacuum chuck 22 at its tip.
3 and rotated 90 degrees so that the opening is inward, and the upper side plate is brought into contact with a predetermined position of the frame 6.

As shown in FIG. 6, a laser beam passage hole 25 is formed in one side plate of the inner shield 7 at the welding position.
In addition, since the frame 6 is set in the inner shield magazine 20 with the side edge on which the laser beam passage hole 25 is formed facing inward, the side edge on the side where the laser beam passage hole is not formed is in contact with the side edge of the frame 6. You will be contacted.

FIG. 7 shows a situation in which the inner shield 7 is welded to the frame 6. While the inner shield 7 is being pressed against the frame 6 by a holder (not shown), a laser beam, for example a YAG laser beam with a wavelength of 1.06 μIn, is applied. 26
passes through the laser beam passage hole 25 described above to the welded part 2.
4.

Reference numeral 27 is a system for illuminating YAG laser light.

On the other hand, the vacuum chuck 22 sucks the air around it at a position slightly away from the inner shield 7 to remove molten metal gas generated during welding work. In addition, air is blown out as needed to aid in gas diffusion and to cool the welded area.

The method of the present invention is not limited to the above examples,
The positioning device can be modified in various ways, and -C can be similarly applied not only to welding the frame and the inner shield, but also to welding the shadow mask and the frame.

[Effects of the Invention] According to the method of the present invention explained above, since metal parts are C-welded using laser light, the welding strength is not affected by the blackened film, and stable welding strength can be obtained. I can do it. According to experiments, in the case of resistance welding, the standard deviation value of weld strength was 0.75 kg, whereas in the case of welding according to the present invention, this was 0.37 kg.

In addition, in conventional resistance welding, it is necessary to apply pressure to the welded part with a force of about 10 g, which causes plastic deformation in the pressurized part, but with the method of the present invention, a force of about several hundred grams is required. The pressure is sufficient and does not cause plastic deformation in the pressurized part.

Furthermore, since laser light such as YAG laser light can locally heat the area, the occurrence of splash can be minimized.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a color cathode ray tube, Fig. 2 is a perspective view of its metal parts, not showing its assembled state, Fig. 3 is a partial longitudinal sectional view showing its assembled state, and Figs. 4 and 5. FIG. 7 is an explanatory diagram of each step of an embodiment of the method of the present invention, and FIG. 6 is a perspective view showing how the inner shield is stored in the inner shield magazine. 1...Panel 4...Shadow mask 6...
......Frame 7...Inner shield 25...
・・・・・・・・・・・・Laser beam passage hole 2G...
・・・・・・・・・・・・YAG Laser Light Representative Patent Attorney Satoshi Suyama - Figure 1 Figure 2 Figure 4 Figure 5

Claims (2)

[Claims] (1) A plurality of metal parts on which a blackened film is formed inside a color cathode ray tube are brought into contact with each other at a predetermined position using a positioning device, and then these are welded using laser light. How to assemble metal parts inside a color cathode ray tube. (2) After forming a blackened film with a cross-sectional shape similar to a U-shape with an enlarged opening, a laser beam passage hole is provided on one side edge of the LC metal component, and the other side edge is attached to another metal component. 2. The method of assembling metal parts in a color cathode ray tube according to claim 1, wherein the metal parts are brought into contact with the metal parts in a color cathode ray tube and the laser light is passed through the laser light passage hole and irradiated on the other side edge.